I rebooted today to find lightdm not starting, and upon attempting to log in through tty2, I got a message saying
Critical error - immediate abort
This is an issue with pam.
I booted a live USB containing Linux Mint (any distro would work, this is called a rescue USB system, and you should always have one). I connected to the wifi, opened the terminal, and did the following:
this showed me my hard disk, named /dev/sda1
sudo mount /dev/sda1 /mnt
this mounts the hard disk
sudo chroot /mnt
this changes the root into my hard disk
cd / ; mount -t proc /proc proc/ ; mount -t sysfs /sys sys/ ; mount --rbind /dev dev/
this is required to set some stuff up after chrooting, see arch wiki
pacman -Si pam pambase | grep Version
this shows the versions of pam and pambase
At this point, I determined that the problem was with pam 1.5.3-1, and thus I had to downgrade. I saw no need to downgrade pambase 20221020-1, since it hasn’t been updated in months.
From here on, I followed the guidelines from the downgrading packages article on arch wiki:
sudo pacman -U /var/cache/pacman/pkg/pam-1.5.2-2-x86_64.pkg.tar.zst
beware that the version of pam might differ in your case, but I used the above command to downgrade pam from 1.5.3-1 to 1.5.2-2.
sudo nano /etc/pacman.conf
use this to add
IgnorePkg = pamto the file. For the moment, we don’t want pam upgrading when we run
sudo pacman -Syu.
I then exited from chroot using
shutdown now, removed the Linux Mint USB, and booted into Manjaro, and started writing this post.
I hope you found this helpful.